The present invention relates to a detachable blade for cutting tool, said blade having the form of a striaght prism of small height, of square cross-section and with side faces presenting trapezoidal teeth.
Detachable blades of this type are already known, preferably made of tungsten carbide, which are removably mounted in housings provided in rotary cutting tools, in which housings they are blocked. These detachable blades offer the advantage that each of their eight main edges, determined at the intersection of their front faces and their side faces, may be used as cutting edge. To this end, it suffices, when one of these edges is worn, to unblock the blade from its housing and change its position so that a fresh edge is in cutting position.
In view of the working conditions of the heretofore known blades whose front faces are flat and are entirely perpendicular to the side faces, it was necessary for them to cut negatively, to allow the successive use of the eight main edges of the blade. Now, machining by negative cut proves to be less advantageous than machining by positive cut. Furthermore, the known blades present flat surfaces in their corners, this rendering these zones particularly sensitive to wear.